Numerous species throughout the animal kingdom have evolved to be completely blind, with some even lacking eyes. Many of these animals that are blind are nocturnal or subterranean, living in dark conditions where other senses play more of a role in their daily routines. Their senses of smell, taste, hearing, and touch are often highly sensitive, allowing these creatures to “see” the world in a completely different way than sighted animals.
Some animals in otherwise sighted species are born or go blind due to a myriad of causes, such as their genetics or traumatic events. Several blind species are troglobites, animals that inhabit caves.
In this article we’ll learn about 8 different species of animals that are blind, their habitats and behaviors, and look at some pictures of them as well.
Let’s have a look!
8 Different Animals That are Blind
1. Eyeless Huntsman Spider
Scientific Name: Sinopoda scurion
While many species in this genus are more characteristic of other huntsman spiders, the eyeless huntsman is distinctive for its lack of eyes and pigmentation. Found in caves in Laos, the eyeless huntsman preys on other cave-dwelling arthropods with great success. These light-colored spiders share their cave habitats with species of fish, crabs, scorpions, and other animals who have adapted to an environment void of light.
The eyeless huntsman is a small spider, reaching only 1/2-inch long with a leg span of approximately 2 inches. While species names often have stories behind them, “scurion” is particularly curious due to its irony: Scurion is the name of a company that makes powerful lights for spelunking, making the darkest caves visible.
2. Kaua’i Cave Wolf Spider
Scientific Name: Adelocosa anops
Another eyeless cave spider, this species is endemic to the Koloa District on the Hawaiian island of Kaua’i. This spider shares characteristics with many other wolf spiders, including carrying its young on its back. While many wolf spider species move quickly about their terrestrial habitats, this cave spider is slower-moving and relies on its sense of touch to detect prey.
Numerous wolf spider species are various shades of brown, gray, and black; this species has silvery hairs covering its abdomen and legs, leading to a pale, ghostly appearance. It’s also relatively small for a wolf spider with a leg span reaching 1 1/2-inches.
3. Star-Nosed Mole
Scientific Name: Condylura cristata
Moles, in general, have poor eyesight. The star-nosed mole is completely blind. Their common name is straightforward: their noses have a star-shaped grouping of 22 tentacles. Like other blind species, this mole has evolved other powerful senses, particularly touch. They use their star-shaped nose and tentacles to feel the world around them. These appendages are so powerful, they move at a speed that creates a blur for the human eye.
Like other moles, this species has a round, stout body and strong, powerful front feet with large claws. Unlike other moles, the star-nosed mole spends much more time above ground and also underwater, where it feeds on a variety of invertebrates. Due to its terrestrial and aquatic habits, this species is more vulnerable to predators than most mole species.
4. Texas Blind Salamander
Scientific Name: Eurycea rathbuni
Like many other blind animal species, the Texas blind salamander has a specific habitat in a small range.This species lives in the caves within the San Marcos Pool of theEdwards Aquifer in Texas. This body of water maintains temperatures around 70- to 73-degrees Fahrenheit, something this — and other — species require for healthy populations.
Because these salamanders are cave dwellers where no light travels, they’ve evolved the ability to live blind. Their “eyes” are still visible but inactive. The purely aquatic Texas blind salamander has external gills that are bright red — a characteristic that shows a stark difference from the all-white body.
Scientific Name: Proteus anguinus
The olm is the Texas blind salamander’s European counterpart. Living in Southeastern Europe, this cave-dwelling salamander shares the red external gills of its American cousin, along with other characteristic features. Olms may live up to 100 years, living in dark aquatic caves. Olms can go several years without eating, a trait that helps them in their sometimes food-scarce habitat. The olms “see” their world through sound, sensing vibrations in the waters and on the ground.
6. Mexican Cavefish (Mexican Tetra)
Scientific Name: Astyanax mexicanus
This is another completely eyeless blind animal. The Mexican tetra has surface and cave-dwelling populations within the species. These two different types vary greatly from one another. The surface-dwellers maintain a social construct like some other tetras, while the cave dwellers are independent of each other.
While many of the eyeless animals on this list went through millions of years of evolution to lose their eyes, the Mexican tetra may have gone a different route. Instead of gene mutations disabling eye development, this tetra’s genes seem to have been “switched off.”
Scientific Name: Hydra (Genus)
Although they resemble sea-dwelling anemones, hydras inhabit freshwater habitats. Their tubular bodies can contract, making them nearly invisible to the naked eye. Hydras come in a variety of colors, including green, gray, cream, orange, and pink. When their bodies are stretched out, they reach 1/2- to 2-inches long, depending on the species.
A tiny “foot” allows these delicate animals to cling to any surface under the water. They move by “walking” with this foot or doing slow somersaults to get to their chosen destination. Like jellyfish, hydras use their stinging tentacles to subdue prey.
8. Yeti Crab
Scientific Name: Kiwa hirsuta
The yeti crab was discovered in 2005 during explorations near hydrothermal vents near Easter Island. Not only was it a new species, but it was also a new genus and family. The genus name “Kiwa” comes from the Polynesian goddess of shellfish.This unusual pale crab is not only eyeless, it is covered in yellowish bristles that give it a hairy appearance. Its common name “yeti” pays homage to the infamous yeti of cryptozoology.
While not much is known about this newer family of crab, scientists on the expeditions noted most of the specimens they encountered were hiding under rocks with only their “hairy” arms sticking out. The waters in hydrothermal vents sometimes reach 700-degrees Fahrenheit and provide a unique habitat for various deep-sea creatures.